Various objects, such as mechanical parts (e.g., aircraft parts), are qualitatively tested. Such testing typically focuses on the identification of cracks (e.g., microcracks in welds) or deformations, the occurrence inconsistencies, and/or the evaluation of sizing or fit (e.g., seal fit). Nondestructive testing techniques may be preferred because they do not permanently alter the object under test, thereby allowing the object to be placed into service after testing or allowing further testing by other means.
Radiography is a commonly used nondestructive testing technique that uses high energy (e.g., ionizing) electromagnetic radiation, such as x-rays and gamma rays, to image the internal structure of various objects. However, the quality of radiographic images may be limited by the composition of the object being visualized. For example, there may be little contrast at the interface between a polymeric body and an ambient air-filled void defined by the polymeric body because the radiodensities of the polymer and ambient air may be too similar. Therefore, the resulting radiographic image may depict a poorly defined void structure.
Radiopaque materials have been used to enhance imaging by providing contrast. Traditional radiopaque fluids have been prepared by dissolving or suspending various radiodense compounds in water. However, traditional radiopaque fluids may be incompatible with certain objects (e.g., may be corrosive) and may limit the conditions (temperature and pressure) under which imaging may be performed.
Accordingly, those skilled in the art continue with research and development efforts in the field of imaging.